I'm not in the mood to do explaining today. I'll do it later.
These are among what I call the cards people would've thought of, but definitely wouldn't ever see print due to templating or possible rules or remembering issues. After all, how many people could remember when you gave your Elven Soldier was given first strike when a lot of people don't even remember it's there when it's a static ability.
This is what I could call a partial echo ability. You could pay it and get a much cheaper creature over two turns, or live with a far more expensive and inferior creature for a while. You even get the opportunity to pay a higher cost for a temporary ability if you have the mana later. :D
There will be quite a few three-colour inclined spells later, although there will be no 3 colour spells. :D